D. Grupe (PSU), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC),
E. A. Hoversten (PSU), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (CRESST/GSFC/UMD),
D. M. Palmer (LANL), T. Sakamoto (NASA/UMBC),
B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU),
M. C. Stroh (PSU), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report
on behalf of the Swift Team:
At 22:27:48 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100213A (trigger=412217). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 349.428, +43.383 which is
RA(J2000) = 23h 17m 43s
Dec(J2000) = +43d 23' 00"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows two main spikes
with a total duration of about 4 sec (we can not reject a short burst).
The peak count rate was ~6000 counts/sec (15-350 keV), at ~2 sec
after the trigger.
The XRT began observing the field at 22:29:00.8 UT, 72.7 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 349.3917, 43.3796 which
is equivalent to:
RA(J2000) = 23h 17m 34.01s
Dec(J2000) = +43d 22' 46.4"
with an uncertainty of 3.2 arcseconds (radius, 90% containment). This
location is 95 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. We
cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
1.11e+21 cm^-2 (Kalberla et al. 2005).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 76 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 16% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag.
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
Burst Advocate for this burst is D. Grupe (grupe AT astro.psu.edu).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)